Microfluidic device for whole blood sample preparation

Abstract

A CD-based device for separating plasma from whole blood includes a substrate, a sedimentation chamber disposed in the substrate, and a collection chamber disposed in the substrate and in fluidic communication with the sedimentation chamber through a siphon channel. The sedimentation chamber includes a plurality of finger-like structures disposed along a radially outward edge of the sedimentation chamber, and protruding radially inward relative to the axis of rotation of the substrate. A method for separating plasma from whole blood using the CD-based device includes introducing a blood sample into the sedimentation chamber, rotating the substrate about an axis of rotation at a first rotational speed to separate the plasma from blood cells, and rotating the substrate about the axis of rotation at a second rotational speed, which is lower than the first rotational speed, to move the plasma from the sedimentation chamber into the collection chamber.

What is claimed is: 
     
       1. A centrifugal device for separating plasma from whole blood, comprising:
 a multilayer substrate having an axis of rotation; 
 a sedimentation chamber disposed in one of the layers of the multilayer substrate and defining an interior volume having a volume of at least 2 mL, the sedimentation chamber comprising a plurality of finger-like structures disposed along a radially outward edge of the sedimentation chamber, the plurality of finger-like structures protruding radially inward relative to the axis of rotation of the multilayer substrate and into the interior volume; and 
 a collection chamber disposed in the multilayer substrate and in fluidic communication with the sedimentation chamber. 
 
     
     
       2. The centrifugal device of  claim 1 , wherein the sedimentation chamber and the collection chamber are connected by a siphon channel. 
     
     
       3. The centrifugal device of  claim 1 , further comprising a sample inlet in fluidic communication with the sedimentation chamber. 
     
     
       4. The centrifugal device of  claim 1 , further comprising a ventilation channel in fluidic communication with the sedimentation chamber and the collection chamber. 
     
     
       5. The centrifugal device of  claim 1 , further comprising a sample outlet in fluidic communication with the collection chamber. 
     
     
       6. The centrifugal device of  claim 1 , further comprising a plurality of sedimentation chambers and a plurality of collection chambers disposed in the multilayer substrate. 
     
     
       7. The centrifugal device of  claim 1 , wherein the multilayer substrate comprises a compact disc. 
     
     
       8. The centrifugal device of  claim 1 , wherein the multilayer substrate comprises multiple layers of polycarbonate. 
     
     
       9. A centrifugal device for separating plasma from whole blood comprising:
 a multilayer substrate having an axis of rotation; 
 an inlet channel disposed in the substrate multilayer and including an inlet hole; 
 a sedimentation chamber disposed in one of the layer of the multilayer substrate and coupled to the inlet channel, the sedimentation chamber defining an interior volume having a volume of at least 2 mL and comprising a plurality of finger-like structures disposed along a radially outward edge of the sedimentation chamber, the plurality of finger-like structures protruding radially inward relative to the axis of rotation of the multilayer substrate and into the interior volume; 
 a collection chamber disposed in the multilayer substrate and at least part of which is radially outward of the sedimentation chamber, the collection chamber in fluidic communication with the sedimentation chamber via a siphon channel; and 
 a ventilation channel disposed in the multilayer substrate and connecting the sedimentation chamber and the collection chamber. 
 
     
     
       10. The device of  claim 9 , further comprising a collection channel connected to the collection chamber and terminating in a collection hole. 
     
     
       11. The device of  claim 10 , further comprising a removable seal disposed above the inlet hole and the collection hole. 
     
     
       12. The centrifugal device of  claim 9 , wherein the multilayer substrate comprises multiple layers of polycarbonate. 
     
     
       13. The centrifugal device of  claim 1 , wherein each of the finger-like structures has a length of about 0.26 inches and a width of about 0.07 inches. 
     
     
       14. The centrifugal device of  claim 1 , wherein the multilayer substrate comprises top and bottom polycarbonate layers having a thickness of about 0.0625 inches.